Once they have germinated, thin the seedlings as you would any other broadcast sown seeds. Allow plenty of room between plants for ease of transplanting.
After all danger of frost has passed it is time to introduce them to their new home in the garden. Celeriac is susceptible to frost in both the spring and fall.
If you choose to plant according to the phases of the moon Celeriac should be planted when the moon is in the3rd Quarter (i.e. waning) and in one of the following Zodiac Signs: Cancer, Scorpio, Pisces, Libra, Capricorn
Space seedlings four to six inches apart in rows 18 to 24 inches apart. Allow for the plants to have adequate breathing room and time to stabilize their growth. Then, maintain them with a regular schedule of care.